Interplay of Monosaccharide Configurations on the Deacetylation with Candida antarctica Lipase-B

Configurational differences in monosaccharides determine the products and selectivity of the transesterification reaction with Candida antarctica lipase-B (CAL-B). The β-anomers of peresterified pyranose monosaccharides tend to yield anomeric deprotection products, while the α-anomers preferentially react at the sixth or fourth position. CAL-B differentiates between enantiomers, either reacting more rapidly with d-enantiomers of monosaccharides or having a different selectivity based on the enantiomer. Pivaloylated and benzoylated saccharides are the limits of the CAL-B transesterification reaction, while lower boiling point alcohols such as MeOH and EtOH can replace n-BuOH as the nucleophilic reagent. Finally, CAL-B can be successfully recycled in both long and short reaction time reactions.